#include "mpu9250_quaternio.h"

#include <math.h>
// See also MPU-9250 Register Map and Descriptions, Revision 4.0, RM-MPU-9250A-00, Rev. 1.4, 9/9/2013 for registers not listed in 
// above document; the MPU9250 and MPU9150 are virtually identical but the latter has a different register map
//
//Magnetometer Registers
#define AK8963_ADDRESS   0x0C
#define AK8963_WHO_AM_I  0x00 // should return 0x48
#define AK8963_INFO      0x01
#define AK8963_ST1       0x02  // data ready status bit 0
#define AK8963_XOUT_L    0x03  // data
#define AK8963_XOUT_H    0x04
#define AK8963_YOUT_L    0x05
#define AK8963_YOUT_H    0x06
#define AK8963_ZOUT_L    0x07
#define AK8963_ZOUT_H    0x08
#define AK8963_ST2       0x09  // Data overflow bit 3 and data read error status bit 2
#define AK8963_CNTL      0x0A  // Power down (0000), single-measurement (0001), self-test (1000) and Fuse ROM (1111) modes on bits 3:0
#define AK8963_ASTC      0x0C  // Self test control
#define AK8963_I2CDIS    0x0F  // I2C disable
#define AK8963_ASAX      0x10  // Fuse ROM x-axis sensitivity adjustment value
#define AK8963_ASAY      0x11  // Fuse ROM y-axis sensitivity adjustment value
#define AK8963_ASAZ      0x12  // Fuse ROM z-axis sensitivity adjustment value

#define SELF_TEST_X_GYRO 0x00                  
#define SELF_TEST_Y_GYRO 0x01                                                                          
#define SELF_TEST_Z_GYRO 0x02

/*#define X_FINE_GAIN      0x03 // [7:0] fine gain
#define Y_FINE_GAIN      0x04
#define Z_FINE_GAIN      0x05
#define XA_OFFSET_H      0x06 // User-defined trim values for accelerometer
#define XA_OFFSET_L_TC   0x07
#define YA_OFFSET_H      0x08
#define YA_OFFSET_L_TC   0x09
#define ZA_OFFSET_H      0x0A
#define ZA_OFFSET_L_TC   0x0B */

#define SELF_TEST_X_ACCEL 0x0D
#define SELF_TEST_Y_ACCEL 0x0E    
#define SELF_TEST_Z_ACCEL 0x0F

#define SELF_TEST_A      0x10

#define XG_OFFSET_H      0x13  // User-defined trim values for gyroscope
#define XG_OFFSET_L      0x14
#define YG_OFFSET_H      0x15
#define YG_OFFSET_L      0x16
#define ZG_OFFSET_H      0x17
#define ZG_OFFSET_L      0x18
#define SMPLRT_DIV       0x19
#define CONFIG           0x1A
#define GYRO_CONFIG      0x1B
#define ACCEL_CONFIG     0x1C
#define ACCEL_CONFIG2    0x1D
#define LP_ACCEL_ODR     0x1E   
#define WOM_THR          0x1F   

#define MOT_DUR          0x20  // Duration counter threshold for motion interrupt generation, 1 kHz rate, LSB = 1 ms
#define ZMOT_THR         0x21  // Zero-motion detection threshold bits [7:0]
#define ZRMOT_DUR        0x22  // Duration counter threshold for zero motion interrupt generation, 16 Hz rate, LSB = 64 ms

#define FIFO_EN          0x23
#define I2C_MST_CTRL     0x24   
#define I2C_SLV0_ADDR    0x25
#define I2C_SLV0_REG     0x26
#define I2C_SLV0_CTRL    0x27
#define I2C_SLV1_ADDR    0x28
#define I2C_SLV1_REG     0x29
#define I2C_SLV1_CTRL    0x2A
#define I2C_SLV2_ADDR    0x2B
#define I2C_SLV2_REG     0x2C
#define I2C_SLV2_CTRL    0x2D
#define I2C_SLV3_ADDR    0x2E
#define I2C_SLV3_REG     0x2F
#define I2C_SLV3_CTRL    0x30
#define I2C_SLV4_ADDR    0x31
#define I2C_SLV4_REG     0x32
#define I2C_SLV4_DO      0x33
#define I2C_SLV4_CTRL    0x34
#define I2C_SLV4_DI      0x35
#define I2C_MST_STATUS   0x36
#define INT_PIN_CFG      0x37
#define INT_ENABLE       0x38
#define DMP_INT_STATUS   0x39  // Check DMP interrupt
#define INT_STATUS       0x3A
#define ACCEL_XOUT_H     0x3B
#define ACCEL_XOUT_L     0x3C
#define ACCEL_YOUT_H     0x3D
#define ACCEL_YOUT_L     0x3E
#define ACCEL_ZOUT_H     0x3F
#define ACCEL_ZOUT_L     0x40
#define TEMP_OUT_H       0x41
#define TEMP_OUT_L       0x42
#define GYRO_XOUT_H      0x43
#define GYRO_XOUT_L      0x44
#define GYRO_YOUT_H      0x45
#define GYRO_YOUT_L      0x46
#define GYRO_ZOUT_H      0x47
#define GYRO_ZOUT_L      0x48
#define EXT_SENS_DATA_00 0x49
#define EXT_SENS_DATA_01 0x4A
#define EXT_SENS_DATA_02 0x4B
#define EXT_SENS_DATA_03 0x4C
#define EXT_SENS_DATA_04 0x4D
#define EXT_SENS_DATA_05 0x4E
#define EXT_SENS_DATA_06 0x4F
#define EXT_SENS_DATA_07 0x50
#define EXT_SENS_DATA_08 0x51
#define EXT_SENS_DATA_09 0x52
#define EXT_SENS_DATA_10 0x53
#define EXT_SENS_DATA_11 0x54
#define EXT_SENS_DATA_12 0x55
#define EXT_SENS_DATA_13 0x56
#define EXT_SENS_DATA_14 0x57
#define EXT_SENS_DATA_15 0x58
#define EXT_SENS_DATA_16 0x59
#define EXT_SENS_DATA_17 0x5A
#define EXT_SENS_DATA_18 0x5B
#define EXT_SENS_DATA_19 0x5C
#define EXT_SENS_DATA_20 0x5D
#define EXT_SENS_DATA_21 0x5E
#define EXT_SENS_DATA_22 0x5F
#define EXT_SENS_DATA_23 0x60
#define MOT_DETECT_STATUS 0x61
#define I2C_SLV0_DO      0x63
#define I2C_SLV1_DO      0x64
#define I2C_SLV2_DO      0x65
#define I2C_SLV3_DO      0x66
#define I2C_MST_DELAY_CTRL 0x67
#define SIGNAL_PATH_RESET  0x68
#define MOT_DETECT_CTRL  0x69
#define USER_CTRL        0x6A  // Bit 7 enable DMP, bit 3 reset DMP
#define PWR_MGMT_1       0x6B // Device defaults to the SLEEP mode
#define PWR_MGMT_2       0x6C
#define DMP_BANK         0x6D  // Activates a specific bank in the DMP
#define DMP_RW_PNT       0x6E  // Set read/write pointer to a specific start address in specified DMP bank
#define DMP_REG          0x6F  // Register in DMP from which to read or to which to write
#define DMP_REG_1        0x70
#define DMP_REG_2        0x71 
#define FIFO_COUNTH      0x72
#define FIFO_COUNTL      0x73
#define FIFO_R_W         0x74
#define WHO_AM_I_MPU9250 0x75 // Should return 0x71
#define XA_OFFSET_H      0x77
#define XA_OFFSET_L      0x78
#define YA_OFFSET_H      0x7A
#define YA_OFFSET_L      0x7B
#define ZA_OFFSET_H      0x7D
#define ZA_OFFSET_L      0x7E

// Define I2C addresses of MPU9250
#define ADO 0
#if ADO
#define MPU9250_ADDRESS 0x69   // Device address when ADO = 1
#else
#define MPU9250_ADDRESS 0x68   // Device address when ADO = 0
#endif  

#define INV_X_GYRO      (0x40)
#define INV_Y_GYRO      (0x20)
#define INV_Z_GYRO      (0x10)
#define INV_XYZ_GYRO    (INV_X_GYRO | INV_Y_GYRO | INV_Z_GYRO)
#define INV_XYZ_ACCEL   (0x08)
#define INV_XYZ_COMPASS (0x01)

#define MAX_PACKET_LENGTH (12)

#define BIT_FIFO_RST        (0x04)
#define BIT_DMP_RST         (0x08)

// unsigned char Ascale = AFS_2G;     // AFS_2G, AFS_4G, AFS_8G, AFS_16G
// unsigned char Gscale = GFS_250DPS; // GFS_250DPS, GFS_500DPS, GFS_1000DPS, GFS_2000DPS
// unsigned char Mscale = MFS_16BITS; // MFS_14BITS or MFS_16BITS, 14-bit or 16-bit magnetometer resolution
// unsigned char Mmode = 0x06;        // Either 8 Hz 0x02) or 100 Hz (0x06) magnetometer data ODR  

// parameters for 6 DoF sensor fusion calculations
// float PI = 3.14159265358979323846f;
float GyroMeasError = PI * (60.0f / 180.0f);     // gyroscope measurement error in rads/s (start at 60 deg/s), then reduce after ~10 s to 3
float beta;
// float beta = sqrt(3.0f / 4.0f) * GyroMeasError;  // compute beta

float deltat = 0.0f;                             // integration interval for both filter schemes

unsigned char mpu9250_quaternio_get_whoiam(mpu9250_quaternio_t *mpu)
{
	unsigned char data;
	mpu->mpu9250_bus_read(MPU9250_ADDRESS, WHO_AM_I_MPU9250, &data, 1);
	return data;
}

signed char mpu9250_quaternio_reset(mpu9250_quaternio_t *mpu)
{
	unsigned char data = 0x80;
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, PWR_MGMT_1, &data, 1);
	mpu->delayms(200);
	return 0;
}

signed char mpu9250_quaternio_DevInit(mpu9250_quaternio_t *mpu)
{
	unsigned char tt;

	beta = sqrt(3.0f / 4.0f) * GyroMeasError;
	// Initialize MPU9250 device
	// wake up device
	tt = 0x00;				// Clear sleep mode bit (6), enable all sensors 
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, PWR_MGMT_1, &tt, 1);
	mpu->delayms(100); // Delay 100 ms for PLL to get established on x-axis gyro; should check for PLL ready interrupt  

	// get stable time source
	tt = 0x01;				// Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, PWR_MGMT_1, &tt, 1);

	// Configure Gyro and Accelerometer
	// Disable FSYNC and set accelerometer and gyro bandwidth to 44 and 42 Hz, respectively; 
	// DLPF_CFG = bits 2:0 = 010; this sets the sample rate at 1 kHz for both
	// Maximum delay is 4.9 ms which is just over a 200 Hz maximum rate
	tt = 0x03;				// Clear sleep mode bit (6), enable all sensors 
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, CONFIG, &tt, 1); 

	// Set sample rate = gyroscope output rate/(1 + SMPLRT_DIV)
	tt = 0x04;				// Use a 200 Hz rate; the same rate set in CONFIG above
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, SMPLRT_DIV, &tt, 1);

	// Set gyroscope full scale range
	// Range selects FS_SEL and AFS_SEL are 0 - 3, so 2-bit values are left-shifted into positions 4:3
	unsigned char c;
	mpu->mpu9250_bus_read(MPU9250_ADDRESS, GYRO_CONFIG, &c, 1); // get current GYRO_CONFIG register value
	// c = c & ~0xE0; // Clear self-test bits [7:5] 
	c = c & ~0x02; // Clear Fchoice bits [1:0] 
	c = c & ~0x18; // Clear AFS bits [4:3]
	c = c | (mpu->Gscale) << 3; // Set full scale range for the gyro
	// c =| 0x00; // Set Fchoice for the gyro to 11 by writing its inverse to bits 1:0 of GYRO_CONFIG
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, GYRO_CONFIG, &c, 1); // Write new GYRO_CONFIG value to register

	// Set accelerometer full-scale range configuration
	mpu->mpu9250_bus_read(MPU9250_ADDRESS, ACCEL_CONFIG, &c, 1); // get current ACCEL_CONFIG register value
	// c = c & ~0xE0; // Clear self-test bits [7:5] 
	c = c & ~0x18;  // Clear AFS bits [4:3]
	c = c | (mpu->Ascale) << 3; // Set full scale range for the accelerometer 
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, ACCEL_CONFIG, &c, 1); // Write new ACCEL_CONFIG register value

	// Set accelerometer sample rate configuration
	// It is possible to get a 4 kHz sample rate from the accelerometer by choosing 1 for
	// accel_fchoice_b bit [3]; in this case the bandwidth is 1.13 kHz
	mpu->mpu9250_bus_read(MPU9250_ADDRESS, ACCEL_CONFIG2, &c, 1); // get current ACCEL_CONFIG2 register value
	c = c & ~0x0F; // Clear accel_fchoice_b (bit 3) and A_DLPFG (bits [2:0])  
	c = c | 0x03;  // Set accelerometer rate to 1 kHz and bandwidth to 41 Hz
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, ACCEL_CONFIG2, &c, 1); // Write new ACCEL_CONFIG2 register value

	// The accelerometer, gyro, and thermometer are set to 1 kHz sample rates, 
	// but all these rates are further reduced by a factor of 5 to 200 Hz because of the SMPLRT_DIV setting

	// Configure Interrupts and Bypass Enable
	// Set interrupt pin active high, push-pull, and clear on read of INT_STATUS, enable I2C_BYPASS_EN so additional chips 
	// can join the I2C bus and all can be controlled by the Arduino as master
	tt = 0x22;				
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, INT_PIN_CFG, &tt, 1);
	tt = 0x01;				// Enable data ready (bit 0) interrupt
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, INT_ENABLE, &tt, 1);

	return 0;
}

signed char mpu9250_quaternio_MagDevInit(mpu9250_quaternio_t *mpu, float * destination)
{
	unsigned char tt;
	// First extract the factory calibration for each magnetometer axis
	unsigned char rawData[3];  // x/y/z gyro calibration data stored here

	tt = 0x00;				// Power down magnetometer  
	mpu->mpu9250_bus_write(AK8963_ADDRESS, AK8963_CNTL, &tt, 1);
	mpu->delayms(100);
	
	tt = 0x0F;				// Enter Fuse ROM access mode
	mpu->mpu9250_bus_write(AK8963_ADDRESS, AK8963_CNTL, &tt, 1);
	mpu->delayms(100);

	mpu->mpu9250_bus_read(AK8963_ADDRESS, AK8963_ASAX, &rawData[0], 3); // Read the x-, y-, and z-axis calibration values
	destination[0] =  (float)(rawData[0] - 128)/256.0f + 1.0f;   // Return x-axis sensitivity adjustment values, etc.
	destination[1] =  (float)(rawData[1] - 128)/256.0f + 1.0f;  
	destination[2] =  (float)(rawData[2] - 128)/256.0f + 1.0f; 


	tt = 0x00;				// Power down magnetometer  
	mpu->mpu9250_bus_write(AK8963_ADDRESS, AK8963_CNTL, &tt, 1);
	mpu->delayms(10);
	// Configure the magnetometer for continuous read and highest resolution
	// set Mscale bit 4 to 1 (0) to enable 16 (14) bit resolution in CNTL register,
	// and enable continuous mode data acquisition Mmode (bits [3:0]), 0010 for 8 Hz and 0110 for 100 Hz sample rates
	tt = (mpu->Mscale) << 4 | (mpu->Mmode);				// Set magnetometer data resolution and sample ODR
	mpu->mpu9250_bus_write(AK8963_ADDRESS, AK8963_CNTL, &tt, 1);
	mpu->delayms(10);


	return 0;
}

signed char mpu9250_quaternio_self_test(mpu9250_quaternio_t *mpu, long *gyro, long *accel, unsigned char hw_test)
{
	unsigned char data[MAX_PACKET_LENGTH];
	unsigned char packet_count, ii;
	unsigned short fifo_count;

	data[0] = 0x01;
	data[1] = 0;
	if(mpu->mpu9250_bus_write(MPU9250_ADDRESS, PWR_MGMT_1, data, 2))
	{
		return -1;
	}
	mpu->delayms(200);

	data[0] = 0;
	if(mpu->mpu9250_bus_write(MPU9250_ADDRESS, INT_ENABLE, data, 1))
	{
		return -1;
	}
	if(mpu->mpu9250_bus_write(MPU9250_ADDRESS, FIFO_EN, data, 1))
	{
		return -1;
	}
	if(mpu->mpu9250_bus_write(MPU9250_ADDRESS, PWR_MGMT_1, data, 1))
	{
		return -1;
	}
	if(mpu->mpu9250_bus_write(MPU9250_ADDRESS, I2C_MST_CTRL, data, 1))
	{
		return -1;
	}
	if(mpu->mpu9250_bus_write(MPU9250_ADDRESS, USER_CTRL, data, 1))
	{
		return -1;
	}


	data[0] = BIT_FIFO_RST | BIT_DMP_RST;
	if(mpu->mpu9250_bus_write(MPU9250_ADDRESS, USER_CTRL, data, 1))
	{
		return -1;
	}
	mpu->delayms(15);

	data[0] = 2; /* 92Hz low pass filter*/
	if(mpu->mpu9250_bus_write(MPU9250_ADDRESS, CONFIG, data, 1))
	{
		return -1;
	}

	data[0] = 0; /* 1kHz. */
	if(mpu->mpu9250_bus_write(MPU9250_ADDRESS, SMPLRT_DIV, data, 1))
	{
		return -1;
	}
	if (hw_test)
		data[0] = 0 | 0xE0; // 0 means 250dps
	else
		data[0] = 0;
	if(mpu->mpu9250_bus_write(MPU9250_ADDRESS, GYRO_CONFIG, data, 1))
	{
		return -1;
	}

	if (hw_test)
		data[0] = 0 | 0xE0; // 0 means Accel FSR setting = 2g
	else
		data[0] = 0;
	if(mpu->mpu9250_bus_write(MPU9250_ADDRESS, ACCEL_CONFIG, data, 1))
	{
		return -1;
	}
	if (hw_test)
		mpu->delayms(200);

	/* Fill FIFO for test.wait_ms milliseconds. */
	data[0] = 0x40; //BIT_FIFO_EN;
	if(mpu->mpu9250_bus_write(MPU9250_ADDRESS, USER_CTRL, data, 1))
	{
		return -1;
	}

	data[0] = INV_XYZ_GYRO | INV_XYZ_ACCEL;
	if(mpu->mpu9250_bus_write(MPU9250_ADDRESS, FIFO_EN, data, 1))
	{
		return -1;
	}

	mpu->delayms(200);
	data[0] = 0;
	if(mpu->mpu9250_bus_write(MPU9250_ADDRESS, FIFO_EN, data, 1))
	{
		return -1;
	}


	if(mpu->mpu9250_bus_read(MPU9250_ADDRESS, FIFO_COUNTH, data, 2))
	{
		return -1;
	}

	fifo_count = (data[0] << 8) | data[1];
	packet_count = fifo_count / MAX_PACKET_LENGTH;
	gyro[0] = gyro[1] = gyro[2] = 0;
	accel[0] = accel[1] = accel[2] = 0;

	for (ii = 0; ii < packet_count; ii++) {

		short accel_cur[3], gyro_cur[3];
		if(mpu->mpu9250_bus_read(MPU9250_ADDRESS, FIFO_R_W, data, MAX_PACKET_LENGTH))
		{
			return -1;
		}
		
		accel_cur[0] = ((short)data[0] << 8) | data[1];
		accel_cur[1] = ((short)data[2] << 8) | data[3];
		accel_cur[2] = ((short)data[4] << 8) | data[5];
		accel[0] += (long)accel_cur[0];
		accel[1] += (long)accel_cur[1];
		accel[2] += (long)accel_cur[2];
		gyro_cur[0] = (((short)data[6] << 8) | data[7]);
		gyro_cur[1] = (((short)data[8] << 8) | data[9]);
		gyro_cur[2] = (((short)data[10] << 8) | data[11]);
		gyro[0] += (long)gyro_cur[0];
		gyro[1] += (long)gyro_cur[1];
		gyro[2] += (long)gyro_cur[2];
	}

    gyro[0] = (long)(((long long)gyro[0]<<16) / (32768/250) / packet_count);
    gyro[1] = (long)(((long long)gyro[1]<<16) / (32768/250) / packet_count);
    gyro[2] = (long)(((long long)gyro[2]<<16) / (32768/250) / packet_count);
    accel[0] = (long)(((long long)accel[0]<<16) / (32768/2) /
        packet_count);
    accel[1] = (long)(((long long)accel[1]<<16) / (32768/2) /
        packet_count);
    accel[2] = (long)(((long long)accel[2]<<16) / (32768/2) /
        packet_count);
    /* Don't remove gravity! */
    if (accel[2] > 0L)
        accel[2] -= 65536L;
    else
        accel[2] += 65536L;

    return 0;
}

signed char mpu9250_quaternio_calibrate(mpu9250_quaternio_t *mpu, float *dest1, float *dest2)
{
	unsigned char data[12]; // data array to hold accelerometer and gyro x, y, z, data
	unsigned char tt;
	unsigned short ii, packet_count, fifo_count;
	signed int gyro_bias[3] = {0, 0, 0}, accel_bias[3] = {0, 0, 0};

	// reset device, reset all registers, clear gyro and accelerometer bias registers
	// writeByte(MPU9250_ADDRESS, PWR_MGMT_1, 0x80); // Write a one to bit 7 reset bit; toggle reset device
	// wait(0.1);  
	mpu9250_quaternio_reset(mpu);

	// get stable time source
	// Set clock source to be PLL with x-axis gyroscope reference, bits 2:0 = 001
	tt = 0x01;
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, PWR_MGMT_1, &tt, 1);
	tt = 0x00;
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, PWR_MGMT_2, &tt, 1);
	mpu->delayms(400);

	// Configure device for bias calculation
	tt = 0x00;				// Disable all interrupts
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, INT_ENABLE, &tt, 1);
	tt = 0x00;				// Disable FIFO
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, FIFO_EN, &tt, 1);
	tt = 0x00;				// Turn on internal clock source
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, PWR_MGMT_1, &tt, 1);
	tt = 0x00;				// Disable I2C master
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, I2C_MST_CTRL, &tt, 1);
	tt = 0x00;				// Disable FIFO and I2C master modes
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, USER_CTRL, &tt, 1);
	tt = 0x0C;				// Reset FIFO and DMP
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, USER_CTRL, &tt, 1);
	mpu->delayms(30);


	// Configure MPU9250 gyro and accelerometer for bias calculation
	tt = 0x01;				// Set low-pass filter to 188 Hz
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, CONFIG, &tt, 1);
	tt = 0x00;				// Set sample rate to 1 kHz
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, SMPLRT_DIV, &tt, 1);
	tt = 0x00;				// Set gyro full-scale to 250 degrees per second, maximum sensitivity
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, GYRO_CONFIG, &tt, 1);
	tt = 0x00;				// Set accelerometer full-scale to 2 g, maximum sensitivity
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, ACCEL_CONFIG, &tt, 1);

	unsigned short  gyrosensitivity  = 131;   // = 131 LSB/degrees/sec
	unsigned short  accelsensitivity = 16384;  // = 16384 LSB/g

	// Configure FIFO to capture accelerometer and gyro data for bias calculation
	tt = 0x40;				// Enable FIFO  
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, USER_CTRL, &tt, 1);
	tt = 0x78;				// Enable gyro and accelerometer sensors for FIFO (max size 512 bytes in MPU-9250)
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, FIFO_EN, &tt, 1);
	mpu->delayms(80);


	// At end of sample accumulation, turn off FIFO sensor read
	tt = 0x00;				// Disable gyro and accelerometer sensors for FIFO
	mpu->mpu9250_bus_write(MPU9250_ADDRESS, FIFO_EN, &tt, 1);
	mpu->mpu9250_bus_read(MPU9250_ADDRESS, FIFO_COUNTH, &data[0], 2); // read FIFO sample count
	fifo_count = ((unsigned short)data[0] << 8) | data[1];
	packet_count = fifo_count/12;// How many sets of full gyro and accelerometer data for averaging

	for (ii = 0; ii < packet_count; ii++) {
		signed short accel_temp[3] = {0, 0, 0}, gyro_temp[3] = {0, 0, 0};
		mpu->mpu9250_bus_read(MPU9250_ADDRESS, FIFO_R_W, &data[0], 12); // read data for averaging
		accel_temp[0] = (signed short) (((signed short)data[0] << 8) | data[1]  ) ;  // Form signed 16-bit integer for each sample in FIFO
		accel_temp[1] = (signed short) (((signed short)data[2] << 8) | data[3]  ) ;
		accel_temp[2] = (signed short) (((signed short)data[4] << 8) | data[5]  ) ;    
		gyro_temp[0]  = (signed short) (((signed short)data[6] << 8) | data[7]  ) ;
		gyro_temp[1]  = (signed short) (((signed short)data[8] << 8) | data[9]  ) ;
		gyro_temp[2]  = (signed short) (((signed short)data[10] << 8) | data[11]) ;

		accel_bias[0] += (signed int) accel_temp[0]; // Sum individual signed 16-bit biases to get accumulated signed 32-bit biases
		accel_bias[1] += (signed int) accel_temp[1];
		accel_bias[2] += (signed int) accel_temp[2];
		gyro_bias[0]  += (signed int) gyro_temp[0];
		gyro_bias[1]  += (signed int) gyro_temp[1];
		gyro_bias[2]  += (signed int) gyro_temp[2];

	}
	accel_bias[0] /= (signed int) packet_count; // Normalize sums to get average count biases
	accel_bias[1] /= (signed int) packet_count;
	accel_bias[2] /= (signed int) packet_count;
	gyro_bias[0]  /= (signed int) packet_count;
	gyro_bias[1]  /= (signed int) packet_count;
	gyro_bias[2]  /= (signed int) packet_count;

	if(accel_bias[2] > 0L) 
	{
		// Remove gravity from the z-axis accelerometer bias calculation
		accel_bias[2] -= (signed int) accelsensitivity;
	}
	else
	{
		accel_bias[2] += (signed int) accelsensitivity;
	}

	// Construct the gyro biases for push to the hardware gyro bias registers, which are reset to zero upon device startup
	data[0] = (-gyro_bias[0]/4  >> 8) & 0xFF; // Divide by 4 to get 32.9 LSB per deg/s to conform to expected bias input format
	data[1] = (-gyro_bias[0]/4)       & 0xFF; // Biases are additive, so change sign on calculated average gyro biases
	data[2] = (-gyro_bias[1]/4  >> 8) & 0xFF;
	data[3] = (-gyro_bias[1]/4)       & 0xFF;
	data[4] = (-gyro_bias[2]/4  >> 8) & 0xFF;
	data[5] = (-gyro_bias[2]/4)       & 0xFF;

	/// Push gyro biases to hardware registers
	/*  writeByte(MPU9250_ADDRESS, XG_OFFSET_H, data[0]);
	writeByte(MPU9250_ADDRESS, XG_OFFSET_L, data[1]);
	writeByte(MPU9250_ADDRESS, YG_OFFSET_H, data[2]);
	writeByte(MPU9250_ADDRESS, YG_OFFSET_L, data[3]);
	writeByte(MPU9250_ADDRESS, ZG_OFFSET_H, data[4]);
	writeByte(MPU9250_ADDRESS, ZG_OFFSET_L, data[5]);
	*/
	dest1[0] = (float) gyro_bias[0]/(float) gyrosensitivity; // construct gyro bias in deg/s for later manual subtraction
	dest1[1] = (float) gyro_bias[1]/(float) gyrosensitivity;
	dest1[2] = (float) gyro_bias[2]/(float) gyrosensitivity;

	// Construct the accelerometer biases for push to the hardware accelerometer bias registers. These registers contain
	// factory trim values which must be added to the calculated accelerometer biases; on boot up these registers will hold
	// non-zero values. In addition, bit 0 of the lower byte must be preserved since it is used for temperature
	// compensation calculations. Accelerometer bias registers expect bias input as 2048 LSB per g, so that
	// the accelerometer biases calculated above must be divided by 8.

	signed int accel_bias_reg[3] = {0, 0, 0}; // A place to hold the factory accelerometer trim biases
	mpu->mpu9250_bus_read(MPU9250_ADDRESS, XA_OFFSET_H, &data[0], 2); // Read factory accelerometer trim values
	accel_bias_reg[0] = (signed short) ((signed short)data[0] << 8) | data[1];
	mpu->mpu9250_bus_read(MPU9250_ADDRESS, YA_OFFSET_H, &data[0], 2); 
	accel_bias_reg[1] = (signed short) ((signed short)data[0] << 8) | data[1];
	mpu->mpu9250_bus_read(MPU9250_ADDRESS, ZA_OFFSET_H, &data[0], 2); 
	accel_bias_reg[2] = (signed short) ((signed short)data[0] << 8) | data[1];

	unsigned int mask = 1uL; // Define mask for temperature compensation bit 0 of lower byte of accelerometer bias registers
	unsigned char mask_bit[3] = {0, 0, 0}; // Define array to hold mask bit for each accelerometer bias axis

	for(ii = 0; ii < 3; ii++)
	{
		if(accel_bias_reg[ii] & mask)
		{
			mask_bit[ii] = 0x01; // If temperature compensation bit is set, record that fact in mask_bit
		}
	}

	// Construct total accelerometer bias, including calculated average accelerometer bias from above
	accel_bias_reg[0] -= (accel_bias[0]/8); // Subtract calculated averaged accelerometer bias scaled to 2048 LSB/g (16 g full scale)
	accel_bias_reg[1] -= (accel_bias[1]/8);
	accel_bias_reg[2] -= (accel_bias[2]/8);

	data[0] = (accel_bias_reg[0] >> 8) & 0xFF;
	data[1] = (accel_bias_reg[0])      & 0xFF;
	data[1] = data[1] | mask_bit[0]; // preserve temperature compensation bit when writing back to accelerometer bias registers
	data[2] = (accel_bias_reg[1] >> 8) & 0xFF;
	data[3] = (accel_bias_reg[1])      & 0xFF;
	data[3] = data[3] | mask_bit[1]; // preserve temperature compensation bit when writing back to accelerometer bias registers
	data[4] = (accel_bias_reg[2] >> 8) & 0xFF;
	data[5] = (accel_bias_reg[2])      & 0xFF;
	data[5] = data[5] | mask_bit[2]; // preserve temperature compensation bit when writing back to accelerometer bias registers

	// Apparently this is not working for the acceleration biases in the MPU-9250
	// Are we handling the temperature correction bit properly?
	// Push accelerometer biases to hardware registers
	/*  writeByte(MPU9250_ADDRESS, XA_OFFSET_H, data[0]);
	writeByte(MPU9250_ADDRESS, XA_OFFSET_L, data[1]);
	writeByte(MPU9250_ADDRESS, YA_OFFSET_H, data[2]);
	writeByte(MPU9250_ADDRESS, YA_OFFSET_L, data[3]);
	writeByte(MPU9250_ADDRESS, ZA_OFFSET_H, data[4]);
	writeByte(MPU9250_ADDRESS, ZA_OFFSET_L, data[5]);
	*/
	// Output scaled accelerometer biases for manual subtraction in the main program
	dest2[0] = (float)accel_bias[0]/(float)accelsensitivity; 
	dest2[1] = (float)accel_bias[1]/(float)accelsensitivity;
	dest2[2] = (float)accel_bias[2]/(float)accelsensitivity;

	return 0;
}

float mpu9250_quaternio_getAres(Ascale_type scale)
{
	switch (scale)
	{
	// Possible accelerometer scales (and their register bit settings) are:
	// 2 Gs (00), 4 Gs (01), 8 Gs (10), and 16 Gs  (11). 
	// Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
		case AFS_2G:
			return (2.0/32768.0);
		case AFS_4G:
			return (4.0/32768.0);
		case AFS_8G:
			return (8.0/32768.0);
		case AFS_16G:
			return (16.0/32768.0);
	}
}

float mpu9250_quaternio_getGres(Gscale_type scale)
{
	switch (scale)
	{
		// Possible gyro scales (and their register bit settings) are:
		// 250 DPS (00), 500 DPS (01), 1000 DPS (10), and 2000 DPS  (11). 
		// Here's a bit of an algorith to calculate DPS/(ADC tick) based on that 2-bit value:
		case GFS_250DPS:
			return (250.0/32768.0);
		case GFS_500DPS:
			return (500.0/32768.0);
		case GFS_1000DPS:
			return (1000.0/32768.0);
		case GFS_2000DPS:
			return (2000.0/32768.0);
	}
}

float mpu9250_quaternio_getMres(Mscale_type scale)
{
	switch (scale)
	{
		// Possible magnetometer scales (and their register bit settings) are:
		// 14 bit resolution (0) and 16 bit resolution (1)
		case MFS_14BITS:
			return (10.0*4912.0/8190.0);
		case MFS_16BITS:
			return (10.0*4912.0/32760.0);
	}
}

void mpu9250_quaternio_update_all_res(mpu9250_quaternio_t *mpu)
{
	mpu->aRes = mpu9250_quaternio_getAres(mpu->Ascale);
	mpu->gRes = mpu9250_quaternio_getGres(mpu->Gscale);
	mpu->mRes = mpu9250_quaternio_getMres(mpu->Mscale);
}

signed char mpu9250_quaternio_get_INT_enable(mpu9250_quaternio_t *mpu)
{
	unsigned char data;
	mpu->mpu9250_bus_read(MPU9250_ADDRESS, INT_STATUS, &data, 1);

	return (data & 0x01) ? 0 : 1;
}

signed char mpu9250_quaternio_read_Acc(mpu9250_quaternio_t *mpu, signed short *acc)
{
	unsigned char rawData[6];  // x/y/z accel register data stored here
	mpu->mpu9250_bus_read(MPU9250_ADDRESS, ACCEL_XOUT_H, &rawData[0], 6); // Read the six raw data registers into data array
	acc[0] = (signed short)(((signed short)rawData[0] << 8) | rawData[1]) ;  // Turn the MSB and LSB into a signed 16-bit value
	acc[1] = (signed short)(((signed short)rawData[2] << 8) | rawData[3]) ;  
	acc[2] = (signed short)(((signed short)rawData[4] << 8) | rawData[5]) ; 
	return 0;
}


signed char mpu9250_quaternio_read_Gyro(mpu9250_quaternio_t *mpu, signed short *gyro)
{
	unsigned char rawData[6];  // x/y/z gyro register data stored here
	mpu->mpu9250_bus_read(MPU9250_ADDRESS, GYRO_XOUT_H, &rawData[0], 6); // Read the six raw data registers sequentially into data array
	gyro[0] = (signed short)(((signed short)rawData[0] << 8) | rawData[1]) ;  // Turn the MSB and LSB into a signed 16-bit value
	gyro[1] = (signed short)(((signed short)rawData[2] << 8) | rawData[3]) ;  
	gyro[2] = (signed short)(((signed short)rawData[4] << 8) | rawData[5]) ; 

	return 0;
}

signed char mpu9250_quaternio_read_Mag(mpu9250_quaternio_t *mpu, signed short *mag)
{
	unsigned char rawData[7];  // x/y/z gyro register data, ST2 register stored here, must read ST2 at end of data acquisition
	mpu->mpu9250_bus_read(AK8963_ADDRESS, AK8963_ST1, &rawData[0], 1); 
	if(rawData[0] & 0x01)
	{ 
		// wait for magnetometer data ready bit to be set
		mpu->mpu9250_bus_read(AK8963_ADDRESS, AK8963_XOUT_L, &rawData[0], 7); // Read the six raw data and ST2 registers sequentially into data array
		unsigned char c = rawData[6]; // End data read by reading ST2 register
		if(!(c & 0x08))
		{
			// Check if magnetic sensor overflow set, if not then report data
			mag[0] = (signed short)(((signed short)rawData[1] << 8) | rawData[0]);  // Turn the MSB and LSB into a signed 16-bit value
			mag[1] = (signed short)(((signed short)rawData[3] << 8) | rawData[2]) ;  // Data stored as little Endian
			mag[2] = (signed short)(((signed short)rawData[5] << 8) | rawData[4]) ; 
		}
	}

	return 0;
}

signed short mpu9250_quaternio_read_Temperature(mpu9250_quaternio_t *mpu)
{
	unsigned char rawData[2];  // x/y/z gyro register data stored here
	readBytes(MPU9250_ADDRESS, TEMP_OUT_H, 2, &rawData[0]);  // Read the two raw data registers sequentially into data array 
	return (signed short)(((signed short)rawData[0]) << 8 | rawData[1]) ;  // Turn the MSB and LSB into a 16-bit value
}

void MadgwickQuaternionUpdate(float ax, float ay, float az, float gx, float gy, float gz, float mx, float my, float mz, float *q)
{
	float q1 = q[0], q2 = q[1], q3 = q[2], q4 = q[3];   // short name local variable for readability
	float norm;
	float hx, hy, _2bx, _2bz;
	float s1, s2, s3, s4;
	float qDot1, qDot2, qDot3, qDot4;

	// Auxiliary variables to avoid repeated arithmetic
	float _2q1mx;
	float _2q1my;
	float _2q1mz;
	float _2q2mx;
	float _4bx;
	float _4bz;
	float _2q1 = 2.0f * q1;
	float _2q2 = 2.0f * q2;
	float _2q3 = 2.0f * q3;
	float _2q4 = 2.0f * q4;
	float _2q1q3 = 2.0f * q1 * q3;
	float _2q3q4 = 2.0f * q3 * q4;
	float q1q1 = q1 * q1;
	float q1q2 = q1 * q2;
	float q1q3 = q1 * q3;
	float q1q4 = q1 * q4;
	float q2q2 = q2 * q2;
	float q2q3 = q2 * q3;
	float q2q4 = q2 * q4;
	float q3q3 = q3 * q3;
	float q3q4 = q3 * q4;
	float q4q4 = q4 * q4;

	// Normalise accelerometer measurement
	norm = sqrt(ax * ax + ay * ay + az * az);
	if (norm == 0.0f) return; // handle NaN
	norm = 1.0f/norm;
	ax *= norm;
	ay *= norm;
	az *= norm;

	// Normalise magnetometer measurement
	norm = sqrt(mx * mx + my * my + mz * mz);
	if (norm == 0.0f) return; // handle NaN
	norm = 1.0f/norm;
	mx *= norm;
	my *= norm;
	mz *= norm;

	// Reference direction of Earth's magnetic field
	_2q1mx = 2.0f * q1 * mx;
	_2q1my = 2.0f * q1 * my;
	_2q1mz = 2.0f * q1 * mz;
	_2q2mx = 2.0f * q2 * mx;
	hx = mx * q1q1 - _2q1my * q4 + _2q1mz * q3 + mx * q2q2 + _2q2 * my * q3 + _2q2 * mz * q4 - mx * q3q3 - mx * q4q4;
	hy = _2q1mx * q4 + my * q1q1 - _2q1mz * q2 + _2q2mx * q3 - my * q2q2 + my * q3q3 + _2q3 * mz * q4 - my * q4q4;
	_2bx = sqrt(hx * hx + hy * hy);
	_2bz = -_2q1mx * q3 + _2q1my * q2 + mz * q1q1 + _2q2mx * q4 - mz * q2q2 + _2q3 * my * q4 - mz * q3q3 + mz * q4q4;
	_4bx = 2.0f * _2bx;
	_4bz = 2.0f * _2bz;

	// Gradient decent algorithm corrective step
	s1 = -_2q3 * (2.0f * q2q4 - _2q1q3 - ax) + _2q2 * (2.0f * q1q2 + _2q3q4 - ay) - _2bz * q3 * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (-_2bx * q4 + _2bz * q2) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + _2bx * q3 * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
	s2 = _2q4 * (2.0f * q2q4 - _2q1q3 - ax) + _2q1 * (2.0f * q1q2 + _2q3q4 - ay) - 4.0f * q2 * (1.0f - 2.0f * q2q2 - 2.0f * q3q3 - az) + _2bz * q4 * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (_2bx * q3 + _2bz * q1) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + (_2bx * q4 - _4bz * q2) * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
	s3 = -_2q1 * (2.0f * q2q4 - _2q1q3 - ax) + _2q4 * (2.0f * q1q2 + _2q3q4 - ay) - 4.0f * q3 * (1.0f - 2.0f * q2q2 - 2.0f * q3q3 - az) + (-_4bx * q3 - _2bz * q1) * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (_2bx * q2 + _2bz * q4) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + (_2bx * q1 - _4bz * q3) * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
	s4 = _2q2 * (2.0f * q2q4 - _2q1q3 - ax) + _2q3 * (2.0f * q1q2 + _2q3q4 - ay) + (-_4bx * q4 + _2bz * q2) * (_2bx * (0.5f - q3q3 - q4q4) + _2bz * (q2q4 - q1q3) - mx) + (-_2bx * q1 + _2bz * q3) * (_2bx * (q2q3 - q1q4) + _2bz * (q1q2 + q3q4) - my) + _2bx * q2 * (_2bx * (q1q3 + q2q4) + _2bz * (0.5f - q2q2 - q3q3) - mz);
	norm = sqrt(s1 * s1 + s2 * s2 + s3 * s3 + s4 * s4);    // normalise step magnitude
	norm = 1.0f/norm;
	s1 *= norm;
	s2 *= norm;
	s3 *= norm;
	s4 *= norm;

	// Compute rate of change of quaternion
	qDot1 = 0.5f * (-q2 * gx - q3 * gy - q4 * gz) - beta * s1;
	qDot2 = 0.5f * (q1 * gx + q3 * gz - q4 * gy) - beta * s2;
	qDot3 = 0.5f * (q1 * gy - q2 * gz + q4 * gx) - beta * s3;
	qDot4 = 0.5f * (q1 * gz + q2 * gy - q3 * gx) - beta * s4;

	// Integrate to yield quaternion
	q1 += qDot1 * deltat;
	q2 += qDot2 * deltat;
	q3 += qDot3 * deltat;
	q4 += qDot4 * deltat;
	norm = sqrt(q1 * q1 + q2 * q2 + q3 * q3 + q4 * q4);    // normalise quaternion
	norm = 1.0f/norm;
	q[0] = q1 * norm;
	q[1] = q2 * norm;
	q[2] = q3 * norm;
	q[3] = q4 * norm;

}

#include "inv_mpu.h"
#include "inv_mpu_dmp_motion_driver.h"
#include "invensense.h"
#include "invensense_adv.h"
#include "eMPL_outputs.h"
#include "mltypes.h"
#include "mpu.h"

void inv_dmp_init(float *acc_b, float *gyro_b)
{
	inv_error_t result;
	result = mpu_init(NULL);
	if (result) {
		printf("Could not initialize gyro.\n");
	}

	long gyro[3], accel[3];

#if defined (MPU6500) || defined (MPU9250)
    result = mpu_run_6500_self_test(gyro, accel, 0);
#elif defined (MPU6050) || defined (MPU9150)
    result = mpu_run_self_test(gyro, accel);
#endif

    printf("self test: %d\r\n", result);
    if (result == 0x7) {
    printf("Passed!\n");
        printf("accel: %7.4f %7.4f %7.4f\n",
                    accel[0]/65536.f,
                    accel[1]/65536.f,
                    accel[2]/65536.f);
        printf("gyro: %7.4f %7.4f %7.4f\n",
                    gyro[0]/65536.f,
                    gyro[1]/65536.f,
                    gyro[2]/65536.f);

        acc_b[0] = accel[0]/65536.f;
        acc_b[1] = accel[1]/65536.f;
        acc_b[2] = accel[2]/65536.f;

        gyro_b[0] = gyro[0]/65536.f;
        gyro_b[1] = gyro[2]/65536.f;
        gyro_b[2] = gyro[2]/65536.f;
        /* Test passed. We can trust the gyro data here, so now we need to update calibrated data*/

        /*
         * This portion of the code uses the HW offset registers that are in the MPUxxxx devices
         * instead of pushing the cal data to the MPL software library
         */
        unsigned char i = 0;

        for(i = 0; i<3; i++) {
          gyro[i] = (long)(gyro[i] * 32.8f); //convert to +-1000dps
          accel[i] *=  2048.f; //convert to +-16G (bug fix from +-8G)
          accel[i] = accel[i] >> 16;
          gyro[i] = (long)(gyro[i] >> 16);
        }

        mpu_set_gyro_bias_reg(gyro);

#if defined (MPU6500) || defined (MPU9250)
        mpu_set_accel_bias_6500_reg(accel);
#elif defined (MPU6050) || defined (MPU9150)
        mpu_set_accel_bias_6050_reg(accel);
#endif
    }
    else {
            if (!(result & 0x1))
                printf("Gyro failed.\n");
            if (!(result & 0x2))
                printf("Accel failed.\n");
            if (!(result & 0x4))
                printf("Compass failed.\n");
     }
}
